Apparatus for regenerating image support from used image-bearing support

ABSTRACT

In a method of and an apparatus for regenerating an image support from a used image-bearing support which bears thereon hydrophobic images formed of thermofusible or heat-softening ink, a plurality of image releasing members are used for removing the hydrophobic images from the used image-bearing support. Specifically, at least one of the image releasing members has a first portion which is able to adhere to the hydrophobic images and a second portion which is unable to adhere to the hydrophobic images, and the image releasing members are arranged in series in order of size of the first portion from small to large along a feeding direction of the used image support. Accordingly, the image releasing members are allowed to adhere to the hydrophobic images in order of size of the first portion from small to large so that the hydrophobic images are removed from the used image support effectively. It is preferable that the image releasing member finally allowed to adhere to the hydrophobic images is a solid image releasing member.

This is a Division of application Ser. No. 08/322,322 filed on Oct. 13,1994, U.S. Pat. No. 5,674,664.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of and an apparatus forregenerating an image support from a used image-bearing or- carryingsupport which bears thereon images formed of thermofusible orheat-softening ink, and more specifically, to a method of and anapparatus for regenerating copying or printing paper from the used onebearing images thereon.

2. Description of the Prior Art

Because of the recent extensive development of the office automation,paper for printers and copying machines has been used and consumed on alarge scale. This has caused serious problems of the globalenvironmental destruction due to large-scale deforestation.

In order to improve the situation, the paper has been recycled byremoving the ink images from the paper, crushing the image-removed paperin water and then re-forming it into a sheet of paper. Conventionally,this was considered to be the only method of recycling the paper.

Recently, however, another method has been developed, which cleans offprinted images from a surface of the used paper and regenerates paperfor further copying or printing.

Examples of the latter recycling method have been described in prior artreferences, which will be introduced hereinbelow:

(1) Japanese First (unexamined) Patent Publication No. 4-64472

A mold-release agent, such as, silicone sealing agent is applied to asurface of non-used copying paper and dried, to produce erasable copyingpaper which can be recycled. Toner images are formed on the mold-releaseagent applied surface of the copying paper.

The image-formed surface of the copying paper is caused to adhere to athermofusible or heat-softening resin (a toner resin as a componentforming the images) to remove the toner images so as to regeneratecopying paper for further use.

The disclosed method, however, has the following disadvantages:

(a) Since the images are formed on the mold-release agent appliedsurface, poor image fixing is inevitably resulted.

(b) The toner images are caused to adhere to the thermofusible orheat-softening resin (toner resin) under the application of heat so asto mechanically peel the images of the surface of the copying paper.However, since the toner resin forming the images permeates into fibersof the copying paper, it is impossible to completely remove the tonerresin, and thus the toner images. Accordingly, the recycling efficiencyof the copying paper is extremely low.

(c) In light of recycling poor resources, double-side copying whereimages are formed on both sides of the copying paper is evaluated highand will be more popular in the future. Under such circumstances, therecycling method where the mold-release agent is applied to only oneside of the copying paper in advance, is evaluated low in efficiency.

(d) On the other hand, when the mold-release agent is applied to bothsides of the copying paper, since a silicone sealing agent as themold-release agent permeates into the copying paper, the resultantcopying paper becomes translucent so that it can not be used for thedouble-side copying.

(e) On a practical basis, it is difficult to make copies with theforegoing erasable copying paper and the plain paper being mixed.Accordingly, the erasable paper and the plain paper should be usedseparately, which is inefficient.

(2) Japanese First (unexamined) Patent Publication Nos. 1-101576 and1-101577

A image-bearing copying paper which bears toner images is immersed intoan organic solvent with which a toner resin forming the images issoluble, and is then applied with an ultrasonic treatment so as toremove the toner images from the copying paper.

However, since the disclosed method employs an organic solvent, therecycled paper is not suitable for general use in offices and homes dueto possible environmental pollution caused by the organic solvent andits combustibility and toxicity.

(3) Japanese First (unexamined) Patent Publication No. 1-297294

An image-bearing support is formed of, such as, plastic, metal, paperhaving low permeability or ceramics. Images on the support are heated inthe presence of a thermofusible or heat-softening separating orreleasing member to be stripped off the support.

The disclosed method, however, requires special erasable paper appliedwith a mold-release treatment to be used. As a result, this method cannot be applied to general copying or printing paper now used widely.

In general, images carried on the image support are roughly classifiedinto two kinds; one being a so-called line image having a relativelysmall print area and thus represented by, such as, a thin character or athin ruled line, and the other being a so-called solid image having arelatively large area and thus represented by, such as, a picture, athick character or a thick ruled line.

As appreciated, the line images have less adhesiveness between the paperfibers and the thermofusible or heat-softening ink as compared with thesolid images since an adhesive area between the paper fibers and theline images are smaller than that between the paper fibers and the solidimages. Further, no adhesion is provided between the line images asopposed to the solid images. As a result, the adhesive strength of theline images is smaller than that of the solid images.

Accordingly, when the conventional method is applied to the imagesupport bearing the images which contain both the line and solid images,since the adhesive strength of the solid images is large as describedabove, the solid images are likely to be either stripped offincompletely or stripped off along with surfaces of the paper fibers.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide animproved method of regenerating an image support from a usedimage-bearing support by effectively removing images formed on the usedimage-bearing support.

It is another object of the present invention to provide an improvedapparatus for regenerating an image support from a used image-bearingsupport by effectively removing images formed on the used image-bearingsupport.

According to one aspect of the present invention, a method ofregenerating an image support from a used image support bearing ahydrophobic image comprises the steps of wetting the used image supportwith at least one of water and an aqueous solution which is selectedfrom the group consisting of an aqueous solution containing asurfactant, an aqueous solution containing a water-soluble polymer andan aqueous solution containing a water-soluble polymer and a surfactant;and causing a plurality of image releasing members to adhere to thehydrophobic image in sequence, under the conditions that the hydrophobicimage is heated at least one of the image releasing members having afirst portion which is able to adhere to the hydrophobic image and asecond portion which is unable to adhere to the hydrophobic image, theplurality of the image releasing members being allowed to adhere to thehydrophobic image in order of size of the first portion from small tolarge so as to remove the hydrophobic image from the used image supportin a wetting state of water or the aqueous solution.

According to another aspect of the present invention, a regeneratingapparatus comprises an image support bearing a hydrophobic image;wetting means for wetting the image support with at least one of waterand an aqueous solution which is selected from the group consisting ofan aqueous solution containing a surfactant, an aqueous solutioncontaining a water-soluble polymer and an aqueous solution containing awater-soluble polymer and a surfactant; and a plurality of imagereleasing members, at least one of the image releasing members having afirst portion which is able to adhere to the hydrophobic image, theplurality of the image releasing members being arranged in series inorder of size of the first portion from small to large along a feedingdirection of the image support so as to remove the hydrophobic imagefrom the image support in a wetting state of water or the aqueoussolution.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood more fully from the detaileddescription given hereinbelow and from the accompanying drawings of thepreferred embodiments of the invention, which are given by way ofexample only, and are not intended to limit the present invention.

In the drawings:

FIG. 1 is a diagram showing an image releasing member in the form of asheet having adhesive portions and non-adhesive portions, to be used inan image support regenerating method according to a preferred embodimentof the present invention;

FIG. 2 is a diagram showing a modification of the image releasing membershown in FIG. 1;

FIG. 3 is a diagram showing a further modification of the imagereleasing member shown in FIG. 1:

FIG. 4 is a diagram showing a further modification of the imagereleasing member shown in FIG. 1;

FIG. 5 is a diagram showing a solid image releasing member in the formof a sheet to be used in the preferred embodiment of the presentinvention:

FIG. 6 is a diagram showing an image releasing member in the form of aroller having adhesive portions and non-adhesive portions, to be used inthe preferred embodiment of the present invention; and

FIG. 7 is a diagram showing schematic structure of an image supportregenerating apparatus according to a preferred embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Now, preferred embodiments of the present invention will be describedhereinbelow with reference to the accompanying drawings.

According to a first preferred embodiment of the present invention, aregenerating method will be described hereinbelow.

In the regenerating method, images formed on a used image support areremoved using a plurality of image separating or releasing members so asto regenerate an image support from the used image-bearing support forfurther use, such as, copying or printing. The image releasing membersto be used in this regenerating method will be described later in detailwith reference to FIGS. 1 to 6.

As the image support, copying or printing paper may be mainly used.However, the image support is not limited to them, but may also beformed of others which can properly carry the images thereon.

Further, the image support is not necessarily composed of only paper inits entirety. Specifically, it is enough for the image support to haveat least one paper layer which includes cellulose fiber as a maincomponent and can carry the hydrophobic images made of thermofusible orheat-softening ink or toner. For example, a laminated composite of paperand plastic layers can be used as the image support.

In the regenerating method, before the hydrophobic images on the usedimage-bearing support and the image releasing members are caused to bein contact with each other, the used image-bearing support isimpregnated with at least water or an aqueous solution which is selectedfrom the group consisting of an aqueous solution containing asurfactant, an aqueous solution containing a water-soluble polymer andan aqueous solution containing a water-soluble polymer and a surfactant.The image support may be impregnated with at least one of the foregoingaqueous solutions and dried before the image support carries the imagesthereon.

As toner component resin of the thermofusible or heat-softening ink tobe removed in this preferred embodiment may be, such as, polystyrene,acrylic resin, methacrylic resin, styrene-butylacrylic copolymer,styrene-butadiene copolymer, polyester or epoxy resin.

In general, when paper is wetted with water, it becomes less stiff. Atthis time, the adhesiveness between the hydrophobic images of thethermofusible or heat-softening ink (toner) carried at the paper layerand the paper layer is extremely weakened.

Specifically, the paper layer made of cellulose fibers as a maincomponent has innumerable irregularities on the surface thereof andinnumerable small clearances inside the paper layer due to the cellulosefibers entwined with each other. When the hydrophobic images are carriedon such a paper layer, each image fixed in a PPC copying process islarger in size than the corresponding one of the irregularities and thesmall clearances so that a number of spaces are formed at a contactportion between the cellulose fibers and the hydrophobic image.

When the image-bearing support bearing such a hydrophobic images isimpregnated with at least one of the foregoing water and aqueoussolution, working as a separating liquid, by means of painting, dipping,spraying or the like, the separating liquid permeates the cellulosefibers and their clearances and spaces due to the capillary action so asto reach the contact portion between the hydrophobic images and thecellulose fibers. Accordingly, the adhesive strength between thehydrophobic images and the cellulose fibers is reduced. In addition,when the cellulose fibers absorb the separating liquid, the cellulosefibers are deformed due to the so-called swelling phenomenon to increasethe spaces at the contact portions with the hydrophobic images, thusreducing contact areas between the cellulose fibers and the hydrophobicimages, which also reduces the adhesive strength between the cellulosefibers and the hydrophobic images. As a result, the adhesiveness betweenthe cellulose fibers and the hydrophobic images are extremely weakened.

Further, in order to release the hydrophobic images from the paper layermore effectively, the foregoing aqueous solution containing thewater-soluble polymer is useful. Specifically, the water-soluble polymeradheres to the hydrophobic images in recessed portions in the paperlayer or in the cellulose fibers which can not directly contact with theimage releasing member, and peels off those hydrophobic images withoutdamaging the paper layer by means of its adhesive strength.

Typical examples of such a water-soluble polymer are shown in Table 1.As appreciated, the present invention is not limited to these examples.

                                      TABLE 1                                     __________________________________________________________________________     ##STR1##                                                                      ##STR2##                                                                     __________________________________________________________________________

                  TABLE 2                                                         ______________________________________                                        Kinds of lipophilic group                                                     ______________________________________                                        Hydrocarbon (composed of carbon chains 6 to 22 in many cases)                 n-alkyl, branching chain alkyl, substitutional alkyl, aromatic,               plural chain alkyl and polyoxyalkylene                                        Partial fluorination alkyl and perfect fluorination alkyl                     Polysiloxane class                                                            ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        Kinds of hydrophilic group                                                    ______________________________________                                        Anionic kind                                                                  carboxylate, sulfonate, sulfate, phosphate and phosphonate                    Cationic kind                                                                 amine salt, quaternary ammonium salt, pyridinium salt, sulfonium salt,        phosphonium salt and polyethylene-polyamine                                   Amphoteric kind                                                               amino acid, betaine, amino sulfate and sulfobetaine                           Nonionic kind                                                                 polyhydric alcohol (glycerol, glucose, sorbitol, cane sugar), amino           alcohol, polyethylene glycol, semipolar bond (amine oxide, sulfoxide,         amineimide)                                                                   ______________________________________                                    

For sufficiently wetting the support paper or the paper layer of theimage support bearing the hydrophobic images of the thermofusible orheat-softening ink (toner) with water in a short time, wettability ofthe image support paper with water is an important factor. Further, forremoving the images from the image support paper, a sufficient amount ofwater is required to permeate into interface between the thermofusibleor heat-softening ink (toner) and the support paper.

In order to facilitate the capillary action and to cause the foregoingseparating liquid to rapidly permeate into the image-bearing supportcarrying the hydrophobic images thereon, a surfactant works effectively.In general, molecules of the surfactant are constituted by a combinationof a lipophilic group and a hydrophilic group. Tables 2 and 3 showexamples of the lipophilic and hydrophilic groups, respectively.However, the present invention is not limited to these examples.

Although many kinds of surfactants are known, anionic surfactants offatty acid derivative, sulfate, suofonic acid and phosphate types, etc.,cationic surfactants of quaternary ammonium salt, heterocyclic amine,amine derivative, etc., an amphoteric surfactant, a nonionic surfactant,etc. are generally enumerated. Typical examples of these surfactants areshown in Tables 4 to 8. Again, the present invention is not limited tothese examples.

                                      TABLE 4                                     __________________________________________________________________________     ##STR3##                                                                      ##STR4##                                                                     __________________________________________________________________________

                                      TABLE 5                                     __________________________________________________________________________    Cationic surfactant                                                           __________________________________________________________________________    1) Aliphatic amine salt and quaternary ammonium salt thereof                   ##STR5##        R.sub.1 = C.sub.12 ˜C.sub.18  R.sub.2, R.sub.3 = H                      or CH.sub.3  X = organic or inorganic acid                                                       (I)                                        ##STR6##        R.sub.1 = C.sub.12 ˜C.sub.18  R.sub.2 = C.sub.12                        ˜C.sub.18, CH.sub.3  X = Cl, Br,                                                           (II)                                      2) Aromatic quaternary ammonium salt                                           ##STR7##        R.sub.1 = C.sub.12 ˜C.sub.18  R.sub.2 = CH.sub.3,                       C.sub.12 ˜C.sub.18  X = Cl, Br, I                                                  (III)                                             3) Heterocyclic quaternary ammonium salt                                       ##STR8##        R.sub.1 = C.sub.12 ˜C.sub.18  X = Cl, Br,                                          (IV)                                               ##STR9##                                                                                       ##STR10## (V)                                               __________________________________________________________________________

                  TABLE 6                                                         ______________________________________                                        Amphoteric surfactant                                                         ______________________________________                                        A.  Betaine                                                                       1. carboxybetaine                                                                            ##STR11##                                                                    (R.sub.1 = C.sub.12 ˜C.sub.18 ; R.sub.2, R.sub.3                        : CH.sub.3, etc; n = 1˜2)                                 2. sulfobetaine                                                                              ##STR12##                                                                    (R.sub.1 = C.sub.12 ˜C.sub.18 ; R.sub.2, R.sub.3                        : CH.sub.3, etc; n = 1˜2)                             B.  Aminocarboxylate                                                                            .sup.+RNH.sub.2 (CH.sub.2).sub.n COO.sup.-                                    (R = C.sub.12 ˜C.sub.18 ; n = 1˜2)              C.  Imidazoline derivative                                                                       ##STR13##                                                                    (R = C.sub.12 ˜C.sub.18)                              ______________________________________                                    

                  TABLE 7                                                         ______________________________________                                        Nonionic surfactant                                                           ______________________________________                                        I.    Ether type                                                                    alkyl and alkyl allyl polyoxy ethylene ether                                  alkyl allyl formaldehyde condensation polyoxy ethylene ether                  block polymer having polyoxy propylene as lipophilic group                    polyoxy ethylene-polyoxy propyl alkyl ether                             II.   Ether ester type                                                              polyoxy ethylene ether of glycerol ester                                      polyoxy ethylene ether of sorbitan ester                                      polyoxy ethylene ether of sorbitol ester                                III.  Ester type                                                                    polyethylene glycol-fatty acid ester                                          glycerol ester                                                                polyglycerol ester                                                            sorbitan ester                                                                propylene glycol ester                                                        cane sugar ester                                                        IV.   Nitrogen-including type                                                       fatty acid alkanol amide                                                      polyoxy ethylene-fatty acid amide                                             polyoxy ethylene-alkyl amine                                                  amine oxide                                                             ______________________________________                                    

                  TABLE 8                                                         ______________________________________                                        Fluorine surfactant                                                           Similar to normal surfactants, there are the following four kinds             of fluorine surfactants.                                                      (1)   anionic type                                                            (2)   nonionic type                                                           (3)   cationic type                                                           (4)   amphoteric type                                                         Typical fluorine surfactants                                                  product names                                                                 ______________________________________                                        fluoroalkyl(C.sub.2 -C.sub.10)carboxylate                                     N-perfluorooctane sulfonyl disodium glutamate                                 3- fluoroalkyl(C.sub.6 -C.sub.11)oxy!-1-alkyl(C.sub.3 -C.sub.4)sodium         sulfonate                                                                     3- ω-fluoroalkanoyl(C.sub.6 -C.sub.8)-N-ethyl amino!-1-propane          sodium sulfonate                                                              N- 3-(perfluorooctane sulfonamine)propyl!-N,N-dimethyl-N-carboxy-             methylene ammonium betaine                                                    fluoroalkyl(C.sub.11 -C.sub.20)carboxylate                                    perfluoroalkyl carboxylate(C.sub.7 -C.sub.13)                                 perfluorooctane sulfonic diethanol amide                                      perfluoroalkyl(C.sub.4 -C.sub.12)sulfonate(Li, K, Na)                         N-propyl-N-(2-hydroxy ethyl)perfluorooctane sulfonamide                       perfluoroalkyl(C.sub.6 -C.sub.10)sulfonamide propyl trimethyl ammonium        salt                                                                          perfluoroalkyl(C.sub.6 -C.sub.10)-N-ethyl sulfonyl glycine salt (K)           bisphosphate(N-perfluorooctyl sulfonyl-N-ethyl amino ethyl                    monoperfluoroalkyl(C.sub.6 -C.sub.16)ethyl phosphate                          ______________________________________                                    

Concentration of a surfactant in the aqueous solution is preferably0.01% to 20%, and more preferably 0.01% to 5%. When the concentration ofthe surfactant is excessively high, paper is provided with conductivityso that re-copying quality is deteriorated. On the other hand,concentration of a water-soluble polymer in the aqueous solution ispreferably 0.1% to 20%, and more preferably 0.5% to 10%. When theconcentration of the water-soluble polymer is excessively high,viscosity of the aqueous solution increases to delay the permeabilityinto the image support.

The surfactants and water-soluble polymers used in this preferredembodiment are used as sizing agents for paper in the papermanufacturing industry. Accordingly, the use of them does not damage thesurface of paper, but rather improves the condition of the surface ofpaper.

Now, the image releasing members to be used in this preferred embodimentwill be described hereinbelow with reference to FIGS. 1 to 6. FIGS. 1 to4 and 6 respectively show the image releasing members each of which hasa surface 1 including first and second portions 2 and 3. The firstportions 2 are formed of an adhesive material and thus adhere to thehydrophobic images on the image-bearing support, and the second portions3 are formed of a non-adhesive material and thus do not adhere to thehydrophobic images. Each of these image releasing members can beproduced by coating the shown pattern with the adhesive material on thesurface 1, formed of the non-adhesive material, of the image releasingmember in the form of, such as, a sheet, a belt or a roller.Alternatively, each of those image releasing members can be produced byforming the shown pattern in the form of recess on the surface 1 and byembedding the adhesive material into the recessed pattern. To thecontrary, each of the image releasing members can be produced by coatingthe shown pattern with the non-adhesive material on the surface 1 whichis formed of the adhesive material. Alternatively, each of the imagereleasing members can be produced by forming the shown pattern in theform of recess on the surface 1 formed of the adhesive material and byembedding the non-adhesive material into the recessed pattern.

According to the foregoing method, the image releasing member can beproduced, wherein the portions which can adhere to the hydrophobicimages on the image support under the conditions that the hydrophobicimage is heated and the portions which can not adhere thereto areprovided on the same plane. On the other hand, another type of the imagereleasing member can be produced by forming the shown pattern in theform of a concavo-convex surface made of the adhesive material. Asappreciated, in this case, convex portions adhere to the hydrophobicimages while concave portions do not adhere to the hydrophobic images.

On the other hand, FIG. 5 shows the image releasing member having thesurface 1 which is all adhesive to the hydrophobic images and thus hasno portion being non-adhesive to the hydrophobic images (hereinafterreferred to as "solid surface 4" or "solid image releasing member").

As described before, in this preferred embodiment, a plurality of theimage releasing members are used for removing the hydrophobic imagesfrom the image-bearing support in a wetting state of water or theaqueous solution. Specifically, the image releasing members to be usedhave different sizes of the adhesive portions therebetween, and theimage releasing members having the smallest sizes of the adhesiveportions is first used to remove portions of the hydrophobic images.Subsequently, the image releasing member having the nest larger sizes ofthe adhesive portions is used to remove portions of the remain images.In this manner, the image releasing members having larger sizes of theadhesive portions are used in turn. By removing the images in thismanner, a large-sized image or even a solid image is divided intosmaller portions so as to be removed. Accordingly, the damage to thecellulose fibers which is otherwise caused when peeling off thelarge-sized or solid image can be effectively prevented. Further, theincomplete removal of the images from the support can also beeffectively prevented so that the large-sized or even solid image can becompletely stripped off the support.

As a result, the hydrophobic images including the large-sized or solidimages can be completely peeled off without damaging the paper layer.Accordingly, the formation of the images and the removal thereof can berepeated to allow the effective recycling of the image support.

The adhesive portion may have a shape of grid or lattice as shown inFIG. 1, a shape of rectangle as shown in FIG. 2, a shape of circle asshown in FIGS. 3 and 4 or a shape of spiral as shown in FIG. 6. Thepresent invention is not limited to those shapes in the figures, but mayhave other shapes as long as they provide similar effects, respectively.

Further, the shapes and/or the sizes of the adhesive portions and/or thenon-adhesive portions in one image releasing member may be the same withor different from each other.

Further, the shapes and/or the sizes of the adhesive portions and/or thenon-adhesive portions between the image releasing members may be thesame with or different from each other.

It is to be noted that the number of the image releasing members is notparticularly limited as long as it is equal to or more than two. On theother hand, it is preferable that the image releasing member to be usedfinally is the solid image releasing member having the solid surface 4with no portion being non-adhesive to the hydrophobic images.

Further, as described before, the image releasing member may be in theform of a sheet, a belt, a roller or the like.

The image releasing members may be formed of the following materials. Itis not necessary that the image releasing members are formed of the samematerial. Specifically, the image releasing members may be formed ofdifferent materials which differ in, such as, adhesive strength,affinity or peeling strength. Whether the images can be peeled off ornot is determined based on relationship between a sum of, such as, theadhesive strength between the images themselves and the adhesivestrength between the images and the paper fibers, and the adhesivestrength between the image releasing member and the images. Accordingly,it is effective to select a material of the image releasing member inconsideration of those adhesive strengths.

The adhesive portion of the image releasing member may be formed of ahigh polymer material, such as, polyethylene terephthalate, polystyrene,polypropylene, acrylic resin, methacrylic resin, epoxy resin,styrene-butylacrylic copolymer, styrene-butadiene copolymer. It isparticularly preferable that the adhesive portion of the image releasingmember is formed of the toner component resin contained in thethermofusible or heat-softening ink or a resin having an SP valuesimilar to that of the toner component resin.

Further, the following component resin of an adhesive may be used as amaterial of the adhesive portion of the image releasing member:

protein resins of glue, gelatin, albumin, casein, etc., carbonhydrateresins of starch, cellulose, composite polysaccharide, such as, gumarabic, tragacanth rubber, etc., thermoplastic resins of polymer andcopolymer of vinyl acetate, acrylic, ethylene copolymer, polyamide,polyester, polyurethane, etc., resins of polychloroprene, nitriterubber, regenerated rubber, SBR, natural rubber, etc.

The present invention is not limited to those materials, but may coverother materials as long as they have the adhesiveness relative to thehydrophobic images, irrespective of whether they are water-soluble ornon-water-soluble.

Further, the resin forming the adhesive portion of the image releasingmember may be used by forming it into a shape of sheet, belt or rollerwith a concavo-convex shape on the surface 1, or by being carried, inthe form of the pattern, on the surface of a sheet, a belt, a tape orthe like made of the non-adhesive material. The latter image releasingmember may be produced by providing an adhesive layer, such as, apressure sensitive adhesive layer of rubber, acrylic, etc., in the formof the pattern, on a supporting body of a cellophane adhesive tape, aKraft paper tape, a polyvinyl chloride tape, an acetate tape or afilament tape. Further, the latter image releasing member may also beproduced by heating to fuse the thermofusible or heat-softening ink(toner) or its component resin onto an OHP sheet in the form of thepattern.

EXAMPLE 1

Copied images including line and solid images and produced by acommercially available plain paper copying machine (Product Name:"IMAGIO 320 FPI" produced by Ricoh Co., Ltd.) were immersed in water.Thereafter, the image releasing member having small-sized adhesiveportions was placed on the copied images, and an integral sheet of thecopied images and the image releasing member was applied with heat andpressure by means of a heating roller to perform removal of the images,that is, to peel off portions of the images.

Subsequently, the image releasing member having larger-sized adhesiveportions was used to peel off portions of the remaining images byapplying heat and pressure.

Finally, the solid image releasing member having no portions beingnon-adhesive to the hydrophobic images was used to peel off theremaining images by applying heat and pressure. As a result, both theline and solid images in the copied images were fully peeled off so thata re-usable paper sheet of a solid colour was regenerated withoutimpairing a surface of the paper sheet.

Further, the foregoing processes were repeated ten times. A result wasthat copied images were the same in equality as those of new copyingpaper.

COMPARATIVE EXAMPLE 1

Only one image releasing member having the adhesive portions and thenon-adhesive portions was used. The other conditions were the same asthose in the foregoing Example 1.

A result was that both the line and solid images were peeled off onlyportions thereof. It was difficult to re-use the regenerated paper on apractical basis.

COMPARATIVE EXAMPLE 2

Only the solid image releasing member was used. The other conditionswere the same as those in the foregoing Example 1.

A result was that the line images were clearly peeled off. On the otherhand, the paper sheet was broken at the solid images. It was verydifficult to re-use the regenerated paper.

COMPARATIVE EXAMPLE 3

The image releasing members having the largest, middle and smallestadhesive portions were prepared and used in the order named. The otherconditions were the same as those in the foregoing Example 1.

A result was that the removal of the images was insufficient with theimages remaining on the paper, the paper fibers were partially peeledoff and the solid images were peeled off at only portions thereof. Itwas difficult to re-use the regenerated paper.

Now, referring to FIG. 7, an apparatus for performing the foregoingregeneration method will be described hereinbelow.

In FIG. 7, numerals 5 to 7 denote image releasing rollers having thesmallest, middle and largest adhesive portions, respectively. Numeral 8denotes a solid image releasing roller having no portions beingnon-adhesive to images formed on a paper sheet 10. Numerals 9 denotesfeed rollers, respectively. As shown in FIG. 7, the paper sheet 10 iswetted by wetting means 11 with at least water or an aqueous solutionwhich is selected from the group consisting of an aqueous solutioncontaining a surfactant, an aqueous solution containing a water-solublepolymer and an aqueous solution containing a water-soluble polymer and asurfactant. Thereafter, the paper sheet 10 is further transferred in adirection of arrow in FIG. 7 so that the image releasing rollers 5 to 8are applied to the paper sheet 10 in the order named so as to peel offthe images on the paper sheet 10 in sequence.

Since the other structure of the regenerating apparatus is known in theart, no further explanation will be made therefor.

It is to be understood that this invention is not to be limited to thepreferred embodiments and modifications described above, and thatvarious changes and modifications may be made without departing from thespirit and scope of the invention as defined in the appended claims.

What is claimed is:
 1. A regenerating apparatus for removing ahydrophobic image from an image support comprising:wetting means forwetting said image support with at least one of water and an aqueoussolution which is selected from the group consisting of an aqueoussolution containing a surfactant, an aqueous solution containing awater-soluble polymer and an aqueous solution containing a water-solublepolymer and a surfactant; and a plurality of image releasing memberscomprising a first portion which is able to adhere to the hydrophobicimage and located downstream of said wetting means, said plurality ofimage releasing members being arranged in series in order of size ofsaid first portion from small to large along a feeding direction of saidimage support so as to remove the hydrophobic image from the imagesupport.
 2. The regenerating apparatus as set forth in claim 1, where atleast one of said plurality of the image releasing members is a solidimage releasing member having a maximum size of said first portion andwherein said solid image releasing member is arranged at a finalposition along the feeding direction of said image support.
 3. Theregenerating apparatus as set forth in claim 1, wherein said imagesupport comprises a paper layer made of cellulose fibers, and whereinsaid hydrophobic image is carried by said paper layer.
 4. Theregenerating apparatus as set forth in claim 1, wherein at least one ofsaid image releasing members has said first portion and a secondportion, wherein said second portion is a nonadhesive material that doesnot adhere to said hydrophobic images on said image-bearing support.